slather » smother

“A huge thank you to X, Y, Z and W for squeezing into their kayaks and
smothering on the sun block for their 58-mile, two-day race…” ("Positive Interest", newsletter of the HIV/AIDS charity Waverley Care, reported by Findlay)

“Smother on crackers or toasted French bread for a March Madness appetite pleaser!
Raisin Apricot Chutney…” (link)

Pretty clearly a blend of “slather on” and “smother with/in”. What makes it somewhat eggcorn-like is the substitution of the relatively frequent verb “smother” for the rare and specialized verb “slather”. And the fact that it’s modestly frequent.